Adopt Group#members page for large groups (> 100 users)

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Fix group test for new member add procedure

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Show only people who have assigned issues in assignee dropdown

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Show only people who have assigned merge requests in assignee dropdown

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Show avatars in ajax user selectbox

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
project_user selectbox with ajax autocomplete

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Add placeholder support for project_users_select_tag

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Restyle issue/mr top filters for list

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Use project_users_select_tag for Issue form and MR form

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Dont render more than 20 group members on Project#members page

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
 Merge branch 'improve_large_groups' into 'master'

Improve for large groupsImprove for large groups

This merge request is a set of patched to improve application for large groups with more then 100 people.

Pages to be improved:
:white_check_mark: Group#members page
:white_check_mark: Project#issues page
:white_check_mark: Project#merge_requests page
:white_check_mark: Project#new_issue page
:white_check_mark: Project#new_mr page
:white_check_mark: Project#members page
Merge branch 'master' of github.com:gitlabhq/gitlabhq